Motor control system for knitting machines



Jan. 19, 1954 J, slBLEY 2,666,313

MOTOR CONTROL SYSTEM FOR KNITTING MACHINES Filed Oct 23, 1948 START 3 AC. SUPPLY D. C. SUPPLY CONTROL SUPPLY JNVENTOR. JAM ES FRED SI BLEY ATTORNEY Patented Jan. 19, 1 95 4 2,666,313 moron eohritot i 'oit MACHINES 7 James Fred sim er-rim, Ga.- Appfi'oation 'ooto'tor 23, 1948, seriai' No. 561131 (01. se -r57) Claims-.-

This' invention relates to motor control sys' tem, and more pafticulai'ly to a rilltitoiicoi'i'tfol system for knitting machin s and the like.

Ari object 61'' this invention is' to provide electrical fil'otor c'ofitrol system fdi knittii'i'g machines which will replace mechanical equipment that was formerly used to start, brake and stop such machine's.

Another object ofmy invention s to provide electrical cdfit'rbl system which "wm 'bTa'ke aiid s'top a knittingifiachine in response to the hia king of a thread, the breaking of a needle, the breaking of a control circuit, the failure of bower supply, orthe" fabric becoming too loose on the inachi'ne,and other similar emer encies.

Another object of my invention is to provide a motor control system which braking action is abplie'd momentarily to stop the motor in response to" trout-1e indicated in a control circuit and in which system the braking action is released promptiy after the motor stopsand is held inoperative while the'troub'le is being refnoved from the control circuit, thus allowing cofnpletely free movement of the working parts of the'fiia'chifie so that the machine can be easily operated by hand manipulation to facilitate rapid "correction of the trouble int/owed.

Another object oif 'niy invent on is to prov de a 'inotoi control system which is siiiib'l'e in design, efficient in operation, inexpensive toihaniifacture and rugged in construction.

Other and further objects and advantages of my invention will be apparent from the following description taken in conne'ctionwith the aocom pahying drawing in which there apnears a layout diagram or a system embodying my invem tion.

In the embodiment chosen for illustration, motor I is connected to operate the knitting machine by direct drive. Motor I is put into ino= tion by pressing start button -3 of start-stop switch 2. Pressing button 3 energizes inagnetic switch 4 by closing a circuit to lines 6 and I. When magnetic switchl is energized by pressing button 3, contacts 8, 9, I0 and II are elosed, allowing current'from lines 5 6, and 1 to'fiow through contacts}! ,9, and III, thus putting moto 'I into motion. When'startbutt'on 3 is released, inag'netic switch 4 is kept energized by now of current from lines 6 and I through contact Ii. Should a thread break after motor I is in motion, or if a needle should jam or break, or if the fabric Should become too Most in the machine, ineans are provided to cause it to stop by closing or contacts in. the stop motion circuit 32. eon- &

closing of electrical contacts upon the j mming.

or breaking of a needle in a hitting machine of khdWi'i 'COhSfiiiiCtiOIi. fi'ntfdl pildifi t' 32"? is connected to an arrangement or "closing "elec' firical ColitaCtS wh n the fabri' iii ITS tOO IOfiS in a knitting machine or construction. Closing of any one or'r'nore'o'f these tidiit'rols oonipletes circuit I2 and energizes the co'il of relay I3. Contacts 8, 9, 1'0 and are liept c'lo'sed by current flowing-through contact point M of relay I3 and contact point I5 of relay Hi to energize the coil of magnetic switch '4. When thecoil of relay I3 is ener ized, contact arm 11 of relay I3 breaks from p int I4 and stops "current flow into magnetic switch 4' and causes contacts '8, 9, I0 and II to open and motor-l to stop. Due to inertia inojtor I will not s'top instantaneously when the now of current ceases when contacts a, sa d It; are opened unless hrakihg action is applied. To causemotor -I to stopquickiy 'when contacts 8, '9 and I 0' are thrown open, means are provided'to cause direct current to How instahtiy through a Winding of motor I when c ntacts" t,

Sand I0 are'o'peiied. 'When the ooii of relay I3 is energized and contact arni I! breaks from point I4 itelose on point Is, causin current from lines Sand 1 to now through Contact point 22 or relay zapohtact jpoi'rit ls'o'f relay I3 and contact point 20 of relay time! I9 to energize magnetic switch 2i causing contacts 21 and 2'5 to close allowing direot ourrent from lines it and 21 to now to motor I causing it to come to an instantaneous stop by' the braking aetion or the direct chrrent. When current flows from line 1 through contact oints 22; 18 and '36, to flow through point '20 it also energizes court! 'of timerie by flowing through the coil to com heotioh 2s and thr ugh interlock 30 onto line "6. Interlook'so was closed When conta'cts" 8, e, To

and II were openedby rhaghetio'switch' 't' ing out. When timer 19 becomes "'ene'rg core is delayed from r'is'irig for epproxi atel one-half to o e second or other predetermined timei due to thevaeuu'm caused by the on sun rounding the "core, or other known delayedaction construction. One-half to one second after timer I9 is ehergizedits core risesto'breakoon tact arm 3| from contact point 20. This throws 3 magnetic switch 2| out and stops the flow of direct current through motor I.

If other means were not provided, opening or clearing contacts in the stop motion circuit 32 would break contact arm H from point 58, deenergize timer I9 and close contact arm (H on point 20. This would reset the complete mechanism to cause direct current to flow through motor I should contacts of stop motion circuit 32 again be closed by manipulation in efforts to correct trouble which had caused the machine to stop. To prevent off and on flow of direct current through motor I by manipulation of the stop motion mechanism while motor I is at rest, relay 33 keeps timer I9 energized so that magnetic switch 2I is kept open by breaking of contact arm 3I from point 20. When relay I3 is energized by closing of any contacts in stop motion circuit 32 (by thread breakage, etc.) contact arm I'I closes on point I8 and current flows from point 36 through relay 33 to connection 29, through interlock 30 and to line 6. When relay 33 is energized, contact 34 closes on contact point 35, thus closing the circuit between lines 6 and I and allowing a continued flow of current through timer I9 to keep contact arm 3I open from contact point 20. Therefore, when contacts of the stop motion mechanism are closed and direct current is caused to flow through motor I, after one-half to one second magnetic switch 2i is thrown open and due to relay 33 direct current .will not be caused to flow through motor I again, regardless of manipulation of the stop motion circuit controls, until start button 3 of startstop switch 2 is pressed to energize magnetic switch 4 to open interlock 30.

Knitting machines are ordinarily provided with take-off rolls, indicated at 31, to keep the knitted fabric under the proper tension as it is fed from the needles. The take-off rolls feed the fabric downward by rotation of the rolls inward. Often these rolls fail to keep the proper tension allowing the fabric to loosen. When the fabric becomes too loose it will drop out of the needles. To prevent this, contact point 38, which is connected to one side of circuit I2, is placed so that the rolls, connected to the other side of circuit I2 through relay I3, will close on contact point 38 when the fabric loosens and thereby energize relay I3. Circuit I2 is a 12 volt A. C. control circuit fed from transformer 39 by 110 or 220 volt circuit 40. Closing of contact 38 closes control circuit I2 in the same manner as would the closing of any other contact in stop motion circuit 32, so that relay I3 is energized and contact arm II breaks from contact point I4 and closes on point I8 causing the same action as described above. By this action current to motor I is interrupted and motor I is braked by the direct current as before.

Should the D. C. supply 42 become interrupted or discontinued, relay 23 would release contact arm M from point 22. When the coil of relay 23 ceases to be energized, breaking of contact arm M from point 22 would stop flow of current from line I causing magnetic switch 4 to release, thus throwing contacts 8, 9 and I out and causing motor I to stop.

to allow current from line I to flow through magnetic switch 4 to keep contacts 3, 9 and III closed to operate motor I. Should circuit I2 become interrupted or discontinued, relay IE will release contact arm 44 from contact point I5 and allow it to close on contact point 43. Breaking of contact arm 44 from point I5 will stop the flow of current from line I through magnetic switch 4. This would cause magnetic switch 4 to release, opening contacts 3, 9 and III causing motor I to stop. Closing of contact arm 44 on contact point 43 would cause current from line I to flow through contact arm 3I and contact point 20 to energize magnetic switch 2I and close contacts 24 and 25. Closing of contacts 24 and 25 causes direct current from D. C. supply line 42 to flow into motor I and instantly cause it to stop. Current from line I would then flow through point 36 to energize timer I9 and one-half to one second after magnetic switch 2I caused braking current to flow through motor I, contact arm 3I would be caused to break from contact point 20, thus stopping flow of current through magnetic switch -2I and releasing contacts 24 and 25 and causing the direct current to cease flowing into motor I. Therefore, interruption of circuit I2 would cause motor I to be disconnected from its current supply and to be instantly stopped by the braking action of the direct current, but within one-half to one second thereafter the direct current would be prevented from further flow through motor I. Relay 33 performs in the same manner as described above to keep timer I3 energized until start button 3 is pressed. With the operation of relay 33, direct current is kept out of motor I when relay I6 is energized by restoration of circuit I2.

When motor I is in motion by supply of current from lines 5, 6, and I through contacts 8, 9 and I3 and it is desirable to bring the motor to a stop, stop button 45 may be pressed. When stop button 45 is pressed, current from line Ii through switch 2 and interlock II to magnetic switch 4 is interrupted causing magnetic switch 4 to release contacts 8, 9, and III to stop the motor.

It will be obvious to those skilled in the art that many modifications and changes can be made without departing from the scope of my invention as defined in the appended claims.

I claim:

1. In a motor control system for knitting machines and the like, the combination of. an electric motor arranged and connected to drive a knitting machine, an alternating current power supply, electrically operated means for connecting said motor to said power supply, a direct current supply, a control circuit having means connected thereto responsive to a faulty needle in said knitting machine and means connected thereto responsive to a broken thread in said knitting machine and means connected thereto responsive to too loose material in said knitting machine and means connected thereto responsive to failure of said alternating current supply and means responsive to failure of said direct current supply, all of said means being operatively arranged to effect the disconnection of said motor from said alternating current power supply and the connection of said motor to said direct current supply, electrically operated means for disconnecting said direct current supply from said motor after a predetermined time, and electrically operated means for maintaining said direct current supply disconnected from said motor until after said motor has been again connected to said alternating current power supply.

2. In a motor control system, the combination of an electric motor, an alternating current power supply, a direct current supply, a normally open starting switch, one side ofsaid switch being connected through the excitation coil of a magnetic switch and through the normally closed contact of a stop motion relay to one Wire of said alternating current power supply, a power supply circuit for said stop motion relay, normally open contacts in said power supply circuit arranged to energize said stop motion relay when closed to open said normally closed contact, the other side of said starting switch being connected to one side of a normally closed stopping switch, the other side of said stopping switch being connected to a second wire of said alternating current power supply and also through the excitation coil of a second magnetic switch and through the contact arm of a relay timer and through the excitation coil of said relay timer to one side of an interlock which is closed when said first mentioned magnetic switch is opened, the other side of said interlock being connected to a wire of said alternating current power supply to complete a circuit with said first mentioned wire, said first mentioned magnetic switch being arranged to connect said electric motor to said alternating current power supply when said starting switch is closed, said second mentioned. magnetic switch being arranged to connect said electric motor to said direct current supp-1y, and means operated by said first mentioned magnetic switch for holding the connection of said electric motor to said alternating current power supply.

JAMES FRED SIBLEY.

References Cited in the file of this patent v UNITED STATES PATENTS Number 

